pptPlex is a plug-in that explores an alternate method for presenting a PowerPoint slide deck. Using pptPlex, you can present your slides as a tour through a zoom able canvas instead of a series of linear slides.
However, once I had downloaded and installed it, it failed to load with an error. Running windows XP SP3, MS Office 2007, when I open PPT I didn’t see any ribbons or options for Plex. Going into Powerpoint Options / Addins, Plex is listed, so I click on Go for managing COM Add-Ins. I get a dialogue showing Plex is disabled with the message: Location: mscoree.dll Load Behaviour: Not loaded. A run-time error occurred during the loading of the COM Add-In.
After a while investigating, I found that getting the Primary Interop Assembly for Office 2007 from Microsoft at this link here, would solve the problem.
PPTplex is really a must have add-in for teachers and alike because it add some originality even if your slides are dull 
Site link: PPTplex Download: Here.
Hi all,
I faced same problem with pptPLEX, it failed to load with an error. Finally, after installing the Primary Interop Assembly as your recommenation. Now it works fine.. great !!..
ARI
thx for that.
when i was preparing presentation, i couldn’t make pptplex ribbon. so that was failed.. i had to show my presentation normally.
maybe next time i can use it.
Even after after installing the Primary Interop Assembly runtime error is continuing. Please advise.
Hi,
the scenario of this solution was a Windows XP Pro with Office 2007. If the solution doesn’t work maybe some other variable is new. If you are successful identifying it, please let us know.
Best of luck!
finally it’s works
thank you so much
i got the same problem when install PPTPlex